Stay adjuster

ABSTRACT

A STAY ADJUSTER IS PROVIDED WITH A HYDRAULIC CYLINDER AND PISTON FOR CHANGING THE LENGTH OF A TENSIVELY LOADED STAY ON A SAILBOAT. ONCE ADJUSTMENT HAS OCCURRED, A MECHANICAL LOCK ON THE STAY MECHANISM MAINTAINS THE STAY ADJUSTER IN A POSITIVELY LOCKED POSITON. A PRESSURE GAUGE COMMUNICATED TO THE INTERIOR OF THE HYDRAULIC CYLINDER   AND PISTON PROVIDES AN INDICATION OF BACKSTAY LOADING DURING STAY ADJUSTMENT.

N 1971 v D. J. RUSSELL 3,620,132

STAY ADJUSTER Filed Sept. 25, 1969 INVENTOR.

DAVID J. RUSSELL RESERVOI R ATTORNEYS United States Patent 3,620,182STAY ADJUSTER David J. Russell, 81 Filbert, Sausalito, Calif.

Filed Sept. 25, 1969, Ser. No. 860,932 Int. Cl. B63h 9/04 U.S. Cl.114-109 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates tostay adjusters for use on sailing craft having adjustable staysincluding in their standing rigging and, more particularly, to ahydraulically actuated stay adjuster.

Hydraulically actuated stay adjusters are known. Typically, such stayadjusters are inserted in a segment of a stay. A hydraulic cylinder isconnected through appropriate linkages to one segment of the stay and apiston fitted interior of the cylinder connected to another segment ofthe stay. By forcing hydraulic fluid interior of the hydraulic pistonand cylinder, the length of such stay adjusters can be changed toprovide various stay loadings and lengths necessary for appropriatetuning of sailboat rigging.

Heretofore, such hydraulic actuated stay adjusters have suffered fromtwo serious disadvantages. First, in order to maintain their adjustment,hydraulic fluid within the cylinder and piston has to be maintainedunder pressure at all times. As hydraulic systems under pressure aresubject to some leakage, such stay adjusters have to be constantlychecked and reset to maintain the desired stay length and tension.

Secondly, such stay adjusters are commonly mounted in a positionoverlying either the tack or clew of a sail. The inevitable fluidleakage occurring from a cylinder and piston having hydraulic fluidtherein under pressure for long intervals of time causes oil to fall onthe sails resulting in unsightly stains which destroy sail appearance.

An object of this invention is to provide a hydraulic backstay adjusterwhich can be moved by hydraulics into a desired setting of length andtension and thereafter can be mechanically locked in its adjustedposition.

An advantage of this invention is that the hydraulic cylinder and pistononly have the hydraulic fluid therein under pressure during adjustmentof the stay; when adjustment is completed and the mechanical lock set,pressure on the hydraulic fluid interior of the cylinder and piston isreduced, arresting the tendency for oil leakage.

A further advantage of this invention is that the mechanical lock ofthis invention prevents inadvertent parting of the stay; while neglectto the tuning of the stay may cause loss in sail efficiency, noinadvertent catastrophic release of the stay can occur in the use ofthis adjuster.

A further feature of this invention is that the mechanical advantageprovided by hydraulics is readily suited to the adjustment of largersailboat riggings having correspondingly greater tensions therein.

A further object of this invention is to provide in a hydraulic stayadjuster a pressure gauge for determining fluid pressure interior of thecylinder and piston.

An advantage of the pressure guage is that it will afford an indicationof stay tension during tuning or adjustment of the rigging.

A further advantage of the pressure guage disclosed in this invention isthat it eleminates the need for more complex tension sensing devicessuch as tuning forks, strain guages and the like, which devices ofteninterfere with the fittings to which stays are fastened.

Other objects, features and advantages of this invention will becomemore apparent after referring to the following specification andattached drawing in which:

FIG. 1 is a side elevation schematic of a Marconi rig sloopincorporating in its backstay, the stay adjuster of this invention andillustrating in broken lines the tuned position of a sail when the stayadjuster is in a contracted position;

FIG. 2 is an enlarged side elevation in partial section illustrating theexpanded disposition of the stay adjuster of this invention and showingin broken lines a contracted position of the stay adjuster of thisinvention; and,

FIG. 3 is an end elevation section along lines 3-3 of FIG. 2.

With reference to FIG. 1, Marconi rigged sloop A is illustrated havingmast 10 held in position by head stay 12, jumpers 14 and backstay 16. Asis illustrated, stay adjuster B of this invention is illustratedinserted in and occupying a segment of backstay 16.

Adjustment of adjuster B to shorten the effective length of the backstaycauses changing of the mast orientation to a configuration shown inbroken lines in FIG. 1. Typically, the lower two-thirds of mast 10 isthrust forwardly. The upper third of the mast flexes arcuatelyrearwardly. The position of the mast and stay illustrated in brokenlines causes flattening of the triangular sail 18 fastened to the mastat its luff 20 and to boom 22 at its foot. As is well known in the art,such flattening of sail 18 is desirable when conditions of heavy windexist.

Referring to FIGS. 2 and 3, stay adjusters B of this invention isillustrated. Stay adjuster B includes piston portion C, cylinder portionD, locking mechanism E, and hydraulic system F.

Piston portion C of the stay adjuster includes rod 30 having clevis 32attached to one end, threaded shank 33 configured in rod 30 at the otherend, and piston 35 fastened therebetween. Typically, piston 35 isprovided with concentric aperture 40 through which rod 30 extends. Thepiston is secured by bolt 36 to rod 30. As is conventional in hydraulicconstruction, the periphery of piston 35 is provided with O-ring seal 37to prevent hydraulic leakage between the sidewalls of the piston and thesidewalls of the cylinder. Likewise, second O-ring seal 38 is providedin piston 35 at aperture 40 to prevent hydraulic leakage along rod 30. Asimilar O-ring seal between rod 30 and end plate 52 of the hydrauliccylinder is shown in coaxial alignment to O-ring 38.

Cylinder section D of the backstay adjuster includes cylindrical sleeve50 capped at its end removed from clevis 32 by first end plate 51 andcapped at its opposite end adjacent clevis 32 by second end plate 52.End plate 51 is secured to the end of cylinder 50 at first annulargroove 54. Likewise, end plate 52 is secured to the opposite end ofcylinder 50 at second annular groove 55. Unlike end plate 51, end plate52 is provided with a raised cylindrical plug 57, which plugincorporates in the cylindrical sidewalls thereof O-ring seal 58 toprevent hydraulic leakage between the sidewalls of cylinder 50 and plug57.

End plates 51 and 52 are urged one towards another by rods 60 and 61,and bolts 62 threadedly secured to the rods. Typically, rods 60 and 61are located at diametrically opposite portions of the section ofcylinder 50 and extend through aligned apertures 51 and 52 in endplates.

These plates 51 and 52 are firmly compressed towards one another by thethreaded engagement between bolts 62 threadedly secured to respectiverods 60 and 61.

Attachment of the cylinder portion D to the backstay is accomplished byvirtue of second clevis 65. Typically, rods 60 and 61 extend away fromcylinder portion D a distance exceeding the stroke of piston mounted rod30. At their respective ends, two bolts 64 secure a rectangular plate 68to each rod 60 and 61. Plate 68 has in turn fastened to the Sidesthereof between rods 60 and 61 two parallel plates 70. Plates 70 whenprovided with aligned apertures through which pin 72 extends provide theclevis structure 65 attaching cylinder section D to the other section ofthe stay. As is apparent, rods 60 and 61 as extending outwardly and awayfrom the cylinder define a spatial interval therebetween, which intervalpermits threaded portion 33 of rod 30 to reciprocally move whenhydraulic movement of the piston relative to the cylinder occurs.

Hydraulic pump mechanism F is schematically illustrated. Typically, endplate 52 defines hydraulic fluid aperture 80 extending therethrough tothe interface between piston 35 and cylinder end plate 52. Hydraulicpiping 82 connected through check valve 83 to lever actuated hydraulicpump 84 and reservoir 85 permits one-Way entry of hydraulic fluid intothe cylinder. Upon actuation of pump 84, hydraulic fluid is withdrawnfrom reservoir 85, passed through check valve 83 and then through piping82 into cylinder 50 between end plate 52 and piston 35.

A pressure gauge 90 is illustrated connected to hydraulic conduit 82between check valve 83 and the interior of the hydraulic cylinder andpiston. When hydraulic movement of the piston relative to the cylinderoccurs, gauge 90 will serve to measure the fluid pressure necessary toeffect such movement. As such pressure will be a direct function of thetension between clevis 32 attached piston portion C and clevis 65attached to cylinder portion D, gauge 90 can be calibrated directly tothe tension being transmitted through stay adjuster B.

To provide for the release of hydraulic pressure, throttle valve 92 ishere shown connected across hydraulic conduit 82 to reservoir 85. Whenrelease of the pressure interior of the cylinder and piston is desiredto relax the adjusted stay, throttle valve 92 can be opened to permitfluid to exit from the cylinder and piston through throttle valve 92 andthen into reservoir 85.

A mechanical lock of the stay is provided in its adjusted position bylocking mechanism E, here illustrated as knurled bolt 97 threadedlysecured to threaded portion 33 or rod 30. Typically, when movement ofpiston 35 interior of cylinder 50 has occurred, bolt 97 will bethreadedly moved on rod 30 to a position of abutment with end plate 51.As is apparent, once knurled bolt 97 is in contact with end plate 51,pressure of the hydraulic fluid interior of the cylinder and piston canbe relaxed.

Operation of the adjustable back stay of this invention can be readilyunderstood with reference to FIG. 2. Assuming that the back stayadjuster B is in the relaxed position illustrated in solid lines in FIG.2, lever actuated hydraulic pump 84 is operated. Fluid from reservoir 85passes through pump 84, check valve 83, conduit 82 and then throughinlet aperture 80 into the interface between hydraulic cylinder 35 andend plate 52 interior of cylinder 50. Typically, hydraulic fluid forcedinto this interval will cause movement of piston 35 away from end plate52. Such movement of the piston 35 away from the end plate 52 can occurand continue until piston 35 occupies the position shown in broken linesabutting end plate 51 at the opposite end of cylinder 50.

When the desired adjustment of the back stay has occurred, knurled bolt97 will be moved on the threaded segment 33 of shaft 30 until it liesagainst end plate 51. In this position, hydraulic pressure interior ofthe cylindar can be relaxed and a mechanical interlock of piston portionC of the backstay adjuster relative to cylinder portion D of thebackstay adjuster will occur.

Relaxing of the backstay adjuster is analogous. Typically, leveractuated pump 84 will be actuated to remove the force of compression oflocking mechanism E onto end plate 51. Thereafter, knurled bolt 97 willbe threadedly moved away from end plate 51 to the new position ofbackstay adjustment. When such movement of knurled bolt 97 has beenmade, throttling valve 92 will be opened. This valve will permit fluidinterior of the cylinder and piston to be discharged through thethrottle valve 92 directly to the reservoir 85. Fluid discharge willoccur until locking mechanism E again seats directly on end plate 51.

It should be apparent to the reader that numerous configurations of acylinder, piston and mechanical lock therebetween could be used topractice this invention. Likewise, while one embodiment of thisinvention has been shown and described, it will be apparent that otheradaptations and modifications of this device can be made withoutdeparting from the true spirit and scope of the invention.

I claim:

1. In a sailboat having a mast, a sail and adjustable tensively loadedrigging extending between a point on said mast and a point on said boatfor deflecting said mast and trimming said sail, a segment of saidadjustable tensively loaded rigging comprising: a hydraulic cylinderhaving means for attachment to said standing rigging at one end anddefining a bore for receiving a piston at the other end; a hydraulicpiston for being received interior of said bore of said cylinder; a rodattached to said piston at one end extending outwardly of the bore ofsaid hydraulic cylinder and having means for attachment to said standingrigging at the other end for completing said segment of said tensivelyloaded rigging; said hydraulic cylinder and said rod being substantiallycoaxial with said rigging; means for introducing fluid within saidcylinder to urge said piston to move in opposition to the tensiveloading of said standing rigging between said hydraulic cylinder andpiston; and means for preventing movement of said piston rod withrespect to said cylinder responsive to tension in said rigging whencylinder movement has caused adjustment of said rigging.

2. The invention of claim 1 and wherein said fluid introducing meansincludes a pressure gauge communicated to said fluid introduced interiorof said cylinder for detecting tensive loading of said rigging segmentduring rigging adjustment.

3. The invention of claim 1 and wherein said movement preventing meansincludes: a plate connected to said cylinder and defining an aperturetherethrough for permitting reciprocating movement of said cylinder rodtherethrough; a locking nut threadedly movable on said cylinder rodtowards and away from said plate for locking said rod with respect tosaid plate after adjustment of said rigging by said cylinder.

References Cited UNITED STATES PATENTS 2,162,441 6/1939 Mead 114-402 X2,861,332 11/1958 Hayden 29-452 3,291,090 12/1966 Sevey 114-109 TRYGVEM. BLIX, Primary Examiner

